# i = 'hello_new_world'
# print(i.split('_'))


# i = 1
# print('000%d' %(i))
#
# print('{:0>4d}'.format(1))
#
# a = ['a' , 'b' ]
# c =''.join(a)
# print(c)

# 字典a = {1: 1}  正确

# a = [1, 2, 3, 4]
# b = [5, 6, 7, 8]
# new_ab = []
# for i in a:
#     new_ab.append(i)
# for i in b:
#     new_ab.append(i)
# print(new_ab)


# sorted()升序排序


